The present invention relates to an electronic key registration system that registers an electronic key device to a communication subject.
An electronic key system for a vehicle verifies a key ID transmitted from an electronic key device. Before using the electronic key system, the key ID that is unique to the vehicle key device is registered together with an encryption key to an electronic control unit (ECU) that manages operations of the electronic key system. Japanese Laid-Open Patent Publication Nos. 7-61328, 2003-148018, and 2004-107959 describe examples of electronic key registration systems.